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Comment: 6. Analysis by EPA Method 7421 will detect total lead, not <br /> organo-lead. Methodology, which has not been formally adopted, for <br /> analysis of organic lead is available from the Department of Health <br /> Services Hazardous Materials Laboratory in Berkeley. <br /> Alternatively, total lead analyses can be performed and compared to <br /> background levels to determine if a potential organo-lead problem <br /> exists. <br /> Response: 6. Selected soil samples will be analyzed for total lead (EPA Method <br /> 7421) to allow comparison with background levels. <br /> Comment: 7. Continuous coring is superior to 18" split spoon samples at five <br /> foot intervals for both logging and sampling purposes. Although <br /> split spoon samples are acceptable, given the alluvial soils <br /> on-site and the dual purpose of the borings, I strongly recommend <br /> continuous cores be utilized. <br /> Response: 7. PGandE prefers to collect soil samples with a split spoon sampler <br /> for logistical reasons. Samples will be collected continuously at <br /> OW-1 to evaluate subsurface strata and at a minimum of five foot <br /> intervals for the remaining wells. Each well will be sampled to a <br /> depth of approximately 16 feet below the water table. Cuttings <br /> will be logged as they are brought to the surface by the hollow <br /> stem augers. Drive sampling (split spoon) frequency will be <br /> increased as dictated by the variability in stratigraphy <br /> encountered in OW-1. Samples will be collected continuously if <br /> necessary. <br />